Pentagon officials have denied US troops are moving out of Iraq, despite the existence of correspondence from a high-ranking general that discusses their “onward movement”.

The memo, which is addressed to the Iraqi defence ministry’s Combined Joint Operations Baghdad, has been confirmed independently by an Iraqi military source, according to reports.

BREAKING: The US military sends a letter to the Iraqi military announcing the “onward movement” of US troops “in due deference to the sovereignty of Iraq & as requested by the Iraqi Parliament & the Iraqi PM”. It’s a withdrawal. pic.twitter.com/tQHSsHTtez

— Liz Sly (@LizSly) January 6, 2020

US Secretary of defence Mark Esper has said the letter is not accurate.

“There’s been no decision whatsoever to leave Iraq,” Mr Esper said.

BREAKING: @EsperDoD says memo on withdrawal is not accurate “there’s been no decision whatsoever to leave Iraq.” pic.twitter.com/52DDhSIIQ2

— Tara Copp (@TaraCopp) January 6, 2020

The United States-led military coalition against Islamic State says it will reposition troops in Iraq, according to the letter.

“Sir, in deference to the sovereignty of the Republic of Iraq, and as requested by the Iraqi Parliament and the Prime Minister, CJTF-OIR will be repositioning forces over the course of the coming days and weeks to prepare for onward movement,” read the letter from US Marine Corps Brigadier General William H. Seely III, commanding general of Task Force Iraq.

“I don’t know what that letter is … We’re trying to find out where that’s coming from, what that is. But there’s been no decision made to leave Iraq. Period,” Mr Esper insisted.

The United States has about 5000 troops in Iraq.

The letter was a poorly worded draft document meant only to underscore increase movement of US forces, the top US military officer told reporters.

“Poorly worded, implies withdrawal. That’s not what’s happening,” US Army General Mark Milley, chairman of the military’s Joint Chiefs of Staff, said, stressing there was no withdrawal being planned.

Tensions have dramatically risen in the Middle East following the US President Donald Trump’s decision to assassinate Iranian general Qassem Soleimani in an airstrike at Baghdad International Airport last week.

Tehran has vowed retaliation, prompting Mr Trump to warn any attack on American troops or assets would trigger a wave of targeted strikes on Iranian targets, including cultural sites.

-with AAP